athalon 64 3000

hey guys, i plan to upgrade to the above on maybe a asus k8v board or a gigabyte ga-k8n or perhaps, depending on the answer to this,a gigabyte ga-k8vnxp.my qestion is, do u need 'special memory' for 64 bit boards,or will my present 512 pc2700 and 256 pc2100(i know, different speeds) work with them.if not, then ill have to go for the gigabyte ga-k8n and buy a 1gb of new ram, which i really dont want to do